This book presents the melt pool monitored-laser additive manufacturing (MPMed-LAM) technology for enhancing forming quality and mechanical performance of key metalic components. Despite progress in metal additive manufacturing (AM) since the 1970s, a large number of challenges remain in synergic controlling both shape and performance due to thermal stress-induced defects and metallurgical flaws. The book reviews key research on melt pool monitoring, forming quality control, microstructure evolution, and mechanical performance in laser additive manufacturing (LAM), providing a foundation for understanding MPMed-LAM of some kinds of metallic components. Divided into four parts, it covers the background, thermal modeling, and detailed analysis of defects, microstructure, dimensional accuracy, corrosion, and mechanical properties of metallic components made via MPMed-LAM. Aimed at professionals in mechanical engineering and materials science-particularly in aero-engine applications, it offers some important insights into the mechanisms and future development potential of this advanced technology.